/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.smartandroid.sa.sherlock.widget;

import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.graphics.drawable.Drawable;
import android.util.TypedValue;
import android.view.View;

import com.smartandroid.sa.sherlock.view.ActionProvider;
import com.smartandroid.sa.sherlock.view.Menu;
import com.smartandroid.sa.sherlock.view.MenuItem;
import com.smartandroid.sa.sherlock.view.SubMenu;
import com.smartandroid.sa.sherlock.view.MenuItem.OnMenuItemClickListener;
import com.smartandroid.sa.sherlock.widget.ActivityChooserModel.OnChooseActivityListener;

/**
 * This is a provider for a share action. It is responsible for creating views
 * that enable data sharing and also to show a sub menu with sharing activities
 * if the hosting item is placed on the overflow menu.
 * <p>
 * Here is how to use the action provider with custom backing file in a
 * {@link MenuItem}:
 * </p>
 * <p>
 * 
 * <pre>
 * <code>
 *  // In Activity#onCreateOptionsMenu
 *  public boolean onCreateOptionsMenu(Menu menu) {
 *      // Get the menu item.
 *      MenuItem menuItem = menu.findItem(R.id.my_menu_item);
 *      // Get the provider and hold onto it to set/change the share intent.
 *      mShareActionProvider = (ShareActionProvider) menuItem.getActionProvider();
 *      // Set history different from the default before getting the action
 *      // view since a call to {@link MenuItem#getActionView() MenuItem.getActionView()} calls
 *      // {@link ActionProvider#onCreateActionView()} which uses the backing file name. Omit this
 *      // line if using the default share history file is desired.
 *      mShareActionProvider.setShareHistoryFileName("custom_share_history.xml");
 *      . . .
 *  }
 * 
 *  // Somewhere in the application.
 *  public void doShare(Intent shareIntent) {
 *      // When you want to share set the share intent.
 *      mShareActionProvider.setShareIntent(shareIntent);
 *  }
 * </pre>
 * 
 * </code>
 * </p>
 * <p>
 * <strong>Note:</strong> While the sample snippet demonstrates how to use this
 * provider in the context of a menu item, the use of the provider is not
 * limited to menu items.
 * </p>
 * 
 * @see ActionProvider
 */
public class ShareActionProvider extends ActionProvider {

	/**
	 * Listener for the event of selecting a share target.
	 */
	public interface OnShareTargetSelectedListener {

		/**
		 * Called when a share target has been selected. The client can decide
		 * whether to handle the intent or rely on the default behavior which is
		 * launching it.
		 * <p>
		 * <strong>Note:</strong> Modifying the intent is not permitted and any
		 * changes to the latter will be ignored.
		 * </p>
		 * 
		 * @param source
		 *            The source of the notification.
		 * @param intent
		 *            The intent for launching the chosen share target.
		 * @return Whether the client has handled the intent.
		 */
		public boolean onShareTargetSelected(ShareActionProvider source,
				Intent intent);
	}

	/**
	 * The default for the maximal number of activities shown in the sub-menu.
	 */
	private static final int DEFAULT_INITIAL_ACTIVITY_COUNT = 4;

	/**
	 * The the maximum number activities shown in the sub-menu.
	 */
	private int mMaxShownActivityCount = DEFAULT_INITIAL_ACTIVITY_COUNT;

	/**
	 * Listener for handling menu item clicks.
	 */
	private final ShareMenuItemOnMenuItemClickListener mOnMenuItemClickListener = new ShareMenuItemOnMenuItemClickListener();

	/**
	 * The default name for storing share history.
	 */
	public static final String DEFAULT_SHARE_HISTORY_FILE_NAME = "share_history.xml";

	/**
	 * Context for accessing resources.
	 */
	private final Context mContext;

	/**
	 * The name of the file with share history data.
	 */
	private String mShareHistoryFileName = DEFAULT_SHARE_HISTORY_FILE_NAME;

	private OnShareTargetSelectedListener mOnShareTargetSelectedListener;

	private OnChooseActivityListener mOnChooseActivityListener;

	/**
	 * Creates a new instance.
	 * 
	 * @param context
	 *            Context for accessing resources.
	 */
	public ShareActionProvider(Context context) {
		super(context);
		mContext = context;
	}

	/**
	 * Sets a listener to be notified when a share target has been selected. The
	 * listener can optionally decide to handle the selection and not rely on
	 * the default behavior which is to launch the activity.
	 * <p>
	 * <strong>Note:</strong> If you choose the backing share history file you
	 * will still be notified in this callback.
	 * </p>
	 * 
	 * @param listener
	 *            The listener.
	 */
	public void setOnShareTargetSelectedListener(
			OnShareTargetSelectedListener listener) {
		mOnShareTargetSelectedListener = listener;
		setActivityChooserPolicyIfNeeded();
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public View onCreateActionView() {
		// Create the view and set its data model.
		ActivityChooserModel dataModel = ActivityChooserModel.get(mContext,
				mShareHistoryFileName);
		ActivityChooserView activityChooserView = new ActivityChooserView(
				mContext);
		activityChooserView.setActivityChooserModel(dataModel);

		// Lookup and set the expand action icon.
		TypedValue outTypedValue = new TypedValue();
		mContext.getTheme().resolveAttribute(
				mContext.getResources().getIdentifier(
						"actionModeShareDrawable", "attr",
						mContext.getPackageName()),
				// mContext.getTheme().resolveAttribute(R.attr.actionModeShareDrawable,
				outTypedValue, true);
		Drawable drawable = mContext.getResources().getDrawable(
				outTypedValue.resourceId);
		activityChooserView.setExpandActivityOverflowButtonDrawable(drawable);
		activityChooserView.setProvider(this);

		// Set content description.
		activityChooserView.setDefaultActionButtonContentDescription(mContext
				.getResources().getIdentifier(
						"abs__shareactionprovider_share_with_application",
						"string", mContext.getPackageName()));
		// .setDefaultActionButtonContentDescription(R.string.abs__shareactionprovider_share_with_application);
		activityChooserView
				.setExpandActivityOverflowButtonContentDescription(mContext
						.getResources().getIdentifier(
								"abs__shareactionprovider_share_with",
								"string", mContext.getPackageName()));
		// .setExpandActivityOverflowButtonContentDescription(R.string.abs__shareactionprovider_share_with);

		return activityChooserView;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public boolean hasSubMenu() {
		return true;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void onPrepareSubMenu(SubMenu subMenu) {
		// Clear since the order of items may change.
		subMenu.clear();

		ActivityChooserModel dataModel = ActivityChooserModel.get(mContext,
				mShareHistoryFileName);
		PackageManager packageManager = mContext.getPackageManager();

		final int expandedActivityCount = dataModel.getActivityCount();
		final int collapsedActivityCount = Math.min(expandedActivityCount,
				mMaxShownActivityCount);

		// Populate the sub-menu with a sub set of the activities.
		for (int i = 0; i < collapsedActivityCount; i++) {
			ResolveInfo activity = dataModel.getActivity(i);
			subMenu.add(0, i, i, activity.loadLabel(packageManager))
					.setIcon(activity.loadIcon(packageManager))
					.setOnMenuItemClickListener(mOnMenuItemClickListener);
		}

		if (collapsedActivityCount < expandedActivityCount) {
			// Add a sub-menu for showing all activities as a list item.
			SubMenu expandedSubMenu = subMenu.addSubMenu(
					Menu.NONE,
					collapsedActivityCount,
					collapsedActivityCount,
					mContext.getString(mContext.getResources().getIdentifier(
							"abs__activity_chooser_view_see_all", "string",
							mContext.getPackageName())));
			// mContext.getString(R.string.abs__activity_chooser_view_see_all));
			for (int i = 0; i < expandedActivityCount; i++) {
				ResolveInfo activity = dataModel.getActivity(i);
				expandedSubMenu
						.add(0, i, i, activity.loadLabel(packageManager))
						.setIcon(activity.loadIcon(packageManager))
						.setOnMenuItemClickListener(mOnMenuItemClickListener);
			}
		}
	}

	/**
	 * Sets the file name of a file for persisting the share history which
	 * history will be used for ordering share targets. This file will be used
	 * for all view created by {@link #onCreateActionView()}. Defaults to
	 * {@link #DEFAULT_SHARE_HISTORY_FILE_NAME}. Set to <code>null</code> if
	 * share history should not be persisted between sessions.
	 * <p>
	 * <strong>Note:</strong> The history file name can be set any time, however
	 * only the action views created by {@link #onCreateActionView()} after
	 * setting the file name will be backed by the provided file.
	 * <p>
	 * 
	 * @param shareHistoryFile
	 *            The share history file name.
	 */
	public void setShareHistoryFileName(String shareHistoryFile) {
		mShareHistoryFileName = shareHistoryFile;
		setActivityChooserPolicyIfNeeded();
	}

	/**
	 * Sets an intent with information about the share action. Here is a sample
	 * for constructing a share intent:
	 * <p>
	 * 
	 * <pre>
	 * <code>
	 *  Intent shareIntent = new Intent(Intent.ACTION_SEND);
	 *  shareIntent.setType("image/*");
	 *  Uri uri = Uri.fromFile(new File(getFilesDir(), "foo.jpg"));
	 *  shareIntent.putExtra(Intent.EXTRA_STREAM, uri.toString());
	 * </pre>
	 * 
	 * </code>
	 * </p>
	 * 
	 * @param shareIntent
	 *            The share intent.
	 * 
	 * @see Intent#ACTION_SEND
	 * @see Intent#ACTION_SEND_MULTIPLE
	 */
	public void setShareIntent(Intent shareIntent) {
		ActivityChooserModel dataModel = ActivityChooserModel.get(mContext,
				mShareHistoryFileName);
		dataModel.setIntent(shareIntent);
	}

	/**
	 * Reusable listener for handling share item clicks.
	 */
	private class ShareMenuItemOnMenuItemClickListener implements
			OnMenuItemClickListener {
		@Override
		public boolean onMenuItemClick(MenuItem item) {
			ActivityChooserModel dataModel = ActivityChooserModel.get(mContext,
					mShareHistoryFileName);
			final int itemId = item.getItemId();
			Intent launchIntent = dataModel.chooseActivity(itemId);
			if (launchIntent != null) {
				mContext.startActivity(launchIntent);
			}
			return true;
		}
	}

	/**
	 * Set the activity chooser policy of the model backed by the current share
	 * history file if needed which is if there is a registered callback.
	 */
	private void setActivityChooserPolicyIfNeeded() {
		if (mOnShareTargetSelectedListener == null) {
			return;
		}
		if (mOnChooseActivityListener == null) {
			mOnChooseActivityListener = new ShareAcitivityChooserModelPolicy();
		}
		ActivityChooserModel dataModel = ActivityChooserModel.get(mContext,
				mShareHistoryFileName);
		dataModel.setOnChooseActivityListener(mOnChooseActivityListener);
	}

	/**
	 * Policy that delegates to the {@link OnShareTargetSelectedListener}, if
	 * such.
	 */
	private class ShareAcitivityChooserModelPolicy implements
			OnChooseActivityListener {
		@Override
		public boolean onChooseActivity(ActivityChooserModel host, Intent intent) {
			if (mOnShareTargetSelectedListener != null) {
				return mOnShareTargetSelectedListener.onShareTargetSelected(
						ShareActionProvider.this, intent);
			}
			return false;
		}
	}
}
